MEXICO CITY--Mexico's state oil giant Pemex on Wednesday reported a nearly US$2.7 billion loss in the first quarter.

Pemex, which provides a third of Mexico's government revenue, had a US$327 million loss in the same quarter of 2013.

The company saw a net loss of US$12.5 billion in 2013.

Mexico's national oil company posted the poor results amid an energy reform driven by President Enrique Pena Nieto, who in December signed a controversial law to open Mexico's oil industry to foreign investment for the first time in 75 years.

Pemex is the seventh largest producer of crude oil in the world, according to the company. In 2005, Pemex produced 3.4 million barrels per day compared with 2.5 million in 2013.

Corporate finance chief Mario Beauregard, in a teleconference with shareholders, said the losses largely stemmed from a 58-percent drop in revenues, due to falling export oil prices, and a 19-percent increase in taxes disbursed.